German Patent Application No. DE 101 10 615 describes a method for producing control pulses for power semiconductors, in particular for the purpose of generating offset control pulses for half-bridges, which pulses are recorded at multiphase converters or DC/DC converters. In this method the reference voltage is shifted by a delay time that corresponds to the offsets, or a PWM signal is shifted by a delay time that corresponds to the duration of the period divided by the number of offsets.
German Patent Application No. DE 101 19 985 A1 describes a device for feeding power into a multi-voltage on-board electrical system of a motor vehicle. This device has a multi-voltage vehicle electrical system situated in a motor vehicle, which system supplies at least one first and one second voltage level, each differing from the reference potential. The multi-voltage vehicle electrical system is powered from at least one electrical energy accumulator. It furthermore includes at least one converter for connecting the two voltage levels. In addition, a feeding arrangement is provided for the external feeding of power into the multi-voltage vehicle electrical system. The mentioned converter can be implemented in the form of a multiphase converter. In such converters, several converter cells of lower capacity are connected in parallel, and the power circuits are clocked in a time-staggered manner. This allows filter components to be dispensed with on account of the effects of destructive interference. Such multiphase converters make it possible to realize the first and second converters using the available phases of a single multiphase converter. To this end, the phases are divided up into converters having the function of a step-down and step-up transformer. Via a switch, the phases are then separated inside the converter, on the input side.
German Patent Application No. DE 10 2007 043 603.5 describes a multiphase DC/DC converter which has a plurality of converter cells that a disposed parallel to each other and are clocked at a time offset. A magnetic measuring bridge is disposed between the outputs of two converter cells in each case.
German Patent Application No. DE 696 17 026 T2 describes a system for charging a battery of accumulators of a motor vehicle from a single-phase voltage source; in this case, the motor vehicle is equipped with a three-phase current drive motor having three windings and an inverter having three interrupters for the supply of the three-phase current motor, and an arrangement is provided for operating said inverter as AC voltage/DC voltage converter having a rectifier voltage step-up stage, which include a first and a second interrupter branch of the inverter, a voltage step-down stage having a third interrupter branch of the inverter, and an arrangement for connecting the center tap of the first and second interrupter branch to the single-phase voltage source, the center tap of the third interrupter branch to the battery for the supply of DC voltage. In the system, the center taps of the first and second interrupter branch are connected to said single-phased voltage source via a first inductivity, which is made up of at least one winding of the three-phase current motor. Furthermore, the center tap of the third interrupter branch is connected to the battery via a second inductivity, which is made up of at least one winding of said three-phase current motor that differs from the winding(s) that form(s) the first inductivity.
An electric vehicle or a so-called plug-in hybrid vehicle, that is to say, a hybrid vehicle whose batteries can be recharged on the electricity network, usually includes at least one three-phase inverter for controlling an electrical three-phase current machine for the traction of the electric vehicle. Such an inverter may also be used for withdrawing energy from the power supply system or for injecting energy into the power supply system, in cooperation with line reactors. This is used in elevator drives or crane drives, for example. In this context, the intermediate circuit is first charged slowly to a voltage just above the rectified system voltage with the aid of a precharge contactor having resistors, whereupon the inverter is employed as boost chopper, which rectifies the three-phase system current or which inverts the direct current in the intermediate circuit into a three-phase current system. In the conventional applications, the system currents are set by the inverter based on the voltage deviation in the intermediate circuit from a setpoint value, and possibly also on the basis of a load current. For use as battery charge device, however, a different type of control of the inverter must be implemented, because in this case the desired quantity to be set is the battery charge current and not the desired intermediate circuit voltage.